Those planning a move overseas might be horrified by the cost of medical
procedures - as reflected in insurance premiums - or pleasantly surprised,
depending on the region.

Expats buying private medical cover will often be shaken by what it costs. But a few might be pleasantly surprised.

Medical procedures carried out in different countries to the same standards and with the same success rates can vary widely in cost.

Research by the Organisation for Economic Co-operation and Development pointed out that a heart bypass in the USA is 50 per cent more expensive than in Canada. This reflects in insurance premiums.

Wage structures in the health professions in different countries pay a huge part in the variations. With some 70 per cent of medical costs attributable to labour, union bargaining power is a decisive factor. High pay rates are a particular feature of the US health care system.

Another factor is professional indemnity insurance, prevalent in litigious societies such as the USA. The more patients seek to sue, the greater the indemnity costs.

Then there is "defensive medicine". To cover themselves against the slightest chance of a negligence claim, doctors order every test imaginable. This again adds to costs, yet invasive tests may, paradoxically, constitute some risk to health.

Much also depends on the nature of the state health care system. In this regard, no two countries are alike.

In the case of America, private patients effectively subsidise the two state-run health care systems, Medicare (for the elderly) and Medicaid (for the poor), economists claim.

They say state purchasing power so forces down prices that the middle classes effectively fund part of the system. Squeezed hospitals turn to insurers and self-payers to stay in profit.

On the other side of the globe, shortage of western-standard hospital care pumps up prices. The owners of a dozen such hospitals in Hong Kong have a free rein to charge what they like because occupancy is 100 per cent and demand unmet. Such units can happily charge three times the going rate for a diagnostic scan.

The degree of price variations is bought home in a new report by the London-based International Federation of Health Plans, representing 100 insurance companies. The average cost of a CT scan for the head is US$82 in Argentina, US$175 in UK and US$566 in America.

The highest prices for what is a routine procedure can be around US$1,672 in America, according to figures from the World Health Organisation and OECD. On the surgical front, average prices for appendix removal are (all US$):

Argentina 953

Spain 2,245

South Africa 3,381

UK 3,408

Chile 4,221

France 4,463

Netherlands 4,498

Switzerland 4,782

New Zealand 5,392

Australia 5,467

USA 8,156

Disparities are smaller, but still significant, on prescription drug charges, the report says. Vytorin, for high cholesterol, costs an average, in US$:

Argentina 31

New Zealand 55

UK 68

Switzerland 70

Spain 80

USA 120

Given such stark variations in care costs, it's hardly surprising that international insurers are "zoning" more assiduously when setting premiums. Until recently, the practice was to split the world into three zones. Now, some insurers are splicing up the globe eight ways.